Treatment of continuous sheets of plastic fabric.



W. E. FULLER, JR. TREATMENT OF coummous SHEETS 0P PLASTIC FABRIGL,

APPLICATION FILED MAY 7, 1910.

1,086,762. Patented Feb 103, 19142 w t T v fii} ii: 1':

k \i Q a ms k.) v k T Wz'ztrzesses: T W J H fizz/622207.- 75M 1744.; Q mf l fy is accomplished in a WILLIAM E. FULLER, 33., OF FALL RIVER, MASSACHUSETTS.

TREATMENT OF CONTINUOUS SHEETS OF PLASTIC FABRIC.

Specification of Letters Patent.

Patented Feb. 10,1914.

Application filed Kay 7, 1910. Serial No. 560,071.

To all whom it may concern Be it known that I, WILLIAM E. FULLER, Jr., a citizen of the United States, residing at Fall River, in the county of Bristol and State of Massachusetts, have invented anew and useful Improvement in the Treatment of Continuous Sheets of Plastic Fabric, of

In the ordinary method of finishing -water-proof cloth, rubber cloth or oil cloth,

the fabric is fed off from a roller and while stretched and kept taut, water-proofing so lution or finishing compound is sprayed or spread u on the surface by means of suit able devices. The fabric thus coated, impregnated or treated, is advanced over heated rollers, or warmed plane surfaces until the solvent of the coating material is dried out, then is wound upon a roll. At the present time, the solvent is driven off or allowed to escape into the atmosphere. In some cases, as in the manufacture of oil cloth, ordinary air is circulated above the cloth and the vapor discharged through an exhaust fan into the open air. In the manufacture of celluloid and sheets of like material, the compound is run out and spread upon a belt or apron conveyor, and air carefully cleansed by washing is circulated over or about it to absorb the solvent of the cellulose or gum. As the solvent evaporates and is carried away, the air contains but a small percentage of what it is capable of absorbing.

The object of the present invention is to so treat continuous sheets which are formed of, or are coated, or impregnated, with dissolved gum, rubber, oleaginous, or cellulose substances or compounds, that the solidifying and hardening of the gum or cellulose desirable and satisfactory manner very rapidly, without interfering with the continuous formation or treatment of the sheet, and the valuable solvent of the gum or cellulose is reclaimed for future use, thereb'y materially shortening the process and producing better results 1 consequent drying with a great reduction in the cost (if-manufacture.

In carrying out this process, the sheets which are formed of, or-coated or impregnated with, dissolved gum, while in a wet condition, and while moving, are, in a closed chamber, sub ected to a circulated current of air which is in such condition that it will take up the solvent vapors. The air during its circulation is conducted through a condenser of any common type for the purpose of precipitating the vapor which it has taken up, thereby recovering the solvent and partially drying the air. It is then conducted to a heater, which again raises its temperature so that it enters the concentration chamber, through which the wet sheet is passing, in a su ciently dry and warm condition to absorb the solvent vapors and hasten the solidification of the gum and of the sheet.

Various forms of apparatus suggest themselves for carrying out this improvement. The accompanying drawings illustrate a simple form of apparatus which may be used for inclosing a section of a continuous sheet of fabric that is being coated or impregnated with, or formed of gum or cellulose substances, and concentrating and condensing the solvent vapors, according to this invention. 7

Figure 1 shows a plan of such an apparatus arranged to recover the solvent of the gum or other coating that is being applied to a continuous sheet of fabric. Fig. 2 shows a side view of the same. Fig. 3 shows an end view.

In the apparatus shown, an endless apron 1, of any suitable material, passes around a drum 2, mounted near one end of the frame, and around a drum 3 that is mounted near the other end on a shaft which is provided with a driving pulley 4:. The upper section of this apron travels through a chamber 5 and is supported by the rolls 6, while the lower section is supported by the rolls 7.

moves with the belt by which it is supwhich is illustrated Y a receptacle 13 for holding the supply of coating or. treating compound, which as stated, may be dissolved gum, rubber, cellulose or any other waterproofing,.or finishing, substance or compound. The solution is conducted from the bottom of the receptaole by a pipe14 that extends above the apron and has suitable openings for distributing the solution on the fabric. It is customary,

in some cases, to spread the compound thus applied, upon the surface of the fabric by a knife-edged blade or plate 15..

The concentration chamber 5, which may be any required size, is desirably connected at the top by a pipe 16 with the inlet ofa fan or blower 17. "The outlet of the fan is connected with a condenser 18 of any common type. At the bottom of the condenser is apipe 19 for drawing off the liquid which is precipitated from the vapors brought into the condenser from the concentration chamher. A pipe 20 leads from the lower part of the condenser to a heater 21, which may be warmed by steam pipes 22, or byany other suitable means. A pipe 23 leads from the heater back to the concentration cham- By means of this apparatus, heated air containing the vapor of the solvent of the gum or other compound which is applied to the sheet, or from which the sheet is formed, is conducted from the concentration chamber to the condenser in which the vapor is precipitated. The air thus relieved of vapor then travels to the heater, where after being warmed, it is returned to the chamber, through which the sheet is continuously traveling.

The concentration chamber which may be any desired length, can be a single compartment, or may be divided into several compartments, and it is made as tight as possible to prevent the entrance of dust and air from the outside. -One or more fans or blowers may be employed for circulating the air through the apparatus, or the fan or blower may be omitted and the air allowed to circulate naturally as a result of its being chilled in the condenser and warmed in the heater. The heater may be any common type and could, if desired, be entirely omitted, in which case the circulation would be effected by the fan or blower. If a sheet of celluloid or other compound were being formed, the dissolved gum or cellulose would be allowed to flow directly upon the traveling apron, upon which it would be evenly distributed by the spreading plate mentioned.

-With the process described, the valuable solvent of the gum, cellulose or other substance or compound which is applied to a fabric for coating or otherwise treating it, to waterproof it or give it the desired surface, or fromwhich the sheet is formed, 1s

recovered and reclaimed for future use,

without interfering with the continuous treating of or formation of the sheet. This results in a material saving in the cost of manufacture of such sheets, and produces a much more uniform product than when the gum or cellulose is allowed to dry naturally as a-result of the free evaporation of the solvent. Furthermore, by the practice of this process, the manufacture of such sheets is hastened, for while the drying of the compound is more uniform, it can be effected more rapidly than in the open.

The invention claimed is:

The improvement in the art of manufacturing continuous sheets of plastic fabric which consists in flowing dissolved plastic material continuously on a traveling belt in the open atmosphere, carrying the sheet thus formed through the atmosphere and allowing the solvent to escape and the deposited material to become partially solidified, then passing the said sheet through a closed chamber and while it is being advanced therethrough subjecting it to a current of cleaned and heated air for absorbing the remaining solvent, conducting away the heated vapor impregnated air and cooling and con- (lensing the vapors for the purpose of pre cipitating the solvent and freeing the air from vapor, and reheating the vapor freed air and returning it to the chamber, whereby the dissolved material is first spread into a sheet that is partially set in the open atmosphere and then its degree of solidification and the period of its hardening,.by removing its solvent and subjecting it to a continuous circulation of the same clean vapor freed air at the requisite temperature, can be accurately controlled.

. WM. E. FULLER, JR.

Witnesses:

-WILLIAM C. GRAY, DONALD BIEGLITZ. 

